H5N1 bug could be a bigger killer than H1N1 if it mutates

SINGAPORE has bought a million doses of a vaccine to protect the people here against the H5N1 bird flu.

The vaccine will arrive by the end of the year.

The bug is particularly scary for Singapore, which sits next to Indonesia, the country with the most cases (163) and deaths (135) from the virus. Vietnam, with the next highest number of cases (115) and deaths (58), is also nearby.

Both countries have already had one death each this year.

Unlike the H1N1 pandemic that swept the globe last year, the H5N1 bug could be a bigger killer by far if it mutates.

Of the 486 people reported to have been infected by H5N1 since 2003, 287 have died. This works out to an almost six-in-10 death rate.

Although the H5N1 virus now cannot spread from human to human, experts fear that it will mutate enough to do so one day.

So before this can happen, the Ministry of Health has acted to secure supplies of the vaccine, since vaccines take a notoriously long time to produce.

The order is being made in advance so that the ministry can avoid being caught flat-footed again, as it was with the H1N1 vaccine last year. The first batch of H1N1 vaccine came last November, more than six months after the pandemic was declared.

The H5N1 vaccine is what is called a “pre-pandemic vaccine” – one made based on existing strains of a virus that could possibly cause a pandemic. It might be slightly or even very different from the actual pandemic strain, since viruses mutate.

The hope is that it will be sufficiently similar to the pandemic strain to provide a high level of protection, should the need arise.

Already, countries such as the United States, Switzerland, Finland and New Zealand have stocked up on this vaccine.

Singapore’s order, which runs into millions of dollars, is with GlaxoSmithKline (GSK).

Explaining the purchase, Health Minister Khaw Boon Wan told The Straits Times that the H5N1 bug remained endemic among chickens and ducks, and that the countries around Singapore have plenty of such infected fowl.

“We have been lucky that the feared mutation has yet to take place. Experts continue to say that it is just a matter of time. “I can only hope that they are wrong; but we need to insure ourselves against the possibility that they may be right,” he said.

Aside from buying the vaccines, Singapore is also stockpiling antivirals and N95 masks, and creating more isolation rooms and intensive care units in hospitals, he said.

Antivirals are drugs that attack the flu virus by reducing its ability to replicate in the body. This often results in less pain and a slightly shorter period of illness.

The pre-pandemic vaccine from GSK comes in two parts – the more expensive adjuvant or booster, and the antigen, which is the actual vaccine.

The two parts are combined just before the vaccine is administered. A much smaller amount of antigen is needed when an adjuvant is used.

Singapore already has about 250,000 doses of GSK adjuvants from its purchase of the H1N1 vaccines.

As these can also be used with the H5N1 antigen, the ministry has saved money from not having to buy as many adjuvants.

A Ministry of Health spokesman said the 250,000 adjuvant doses are worth an estimated $3 million. The total cost of the million doses is confidential as it was the result of a tender, he said.

Of the 1.3 million doses of H1N1 vaccine bought last year, more than 850,000 doses are still available.

The ministry estimates that about 430,000 people here have already been infected by H1N1, although only 13,450 cases have laboratory confirmation.

H1N1 killed 21 people here, including the very young. This is mild, relative to the seasonal flu, which kills about 600 people a year here.